The only physical turnoff for me would have to be smokers, sorry but you're ruining your health and I don't want any of that second hand smoke.

The personality turnoffs are usually the ones you have to dig deeper and have known the person for awhile to figure out. For example a very emotionless/passive person that is ok with everything you do or say not because they're "nice" but because they could care less about you. I also can't deal with people I find overly arrogant - not saying you can't be a bit cocky but there's a point when it crosses the line.

Mentally/Emotionally
*I'll try and be a bit specific since some of these cover too much
A lack of brashness (if I have to ask "what's wrong?" 30 times and get responded to with "Nothing" when something clearly is)

Social Butterflies (having 100 friends and are not really genuine with any of them ... liking a lot of people or having a lot of friends is fine if you have a few close friends that know you for you)

Ultra-Religious (being religious is fine but there is a limit)

Ultra-Conservative (self explanatory)

Is an Alcoholic or into drugs (having a few drinks is fine but if it's a bottle of wine every day ... )

People who are purposefully argumentative. They NEVER want to agree with you, even on the tiniest of things. You HAVE to be wrong, always. That goes with people are are always negative. People who are purposefully argumentative are usually OVERLY cynical, and proud of it. Always look on the bright side of life, right?

bad breath, my friend and i were club hopping and when he talked to me, it smelt like a dumpster. lol. i gave him gum and told him but he said he doesnt like chewing gum, he still didnt take it, but we still got girls. i wonder what thought of it. haha

I understand how we should do our best to preserve what we have but... what could ONE person do that would make it a turn off? be a litter bug? or be a ceo of a chemical company that dumps into rivers?